A move is on within Cy Vance Jr.’s campaign for Manhattan District Attorney to curtail the role of a former top deputy to Robert Morgenthau, who sources told The Post had been trying to recruit current assistant DAs – a violation of a long-held office policy.

Sources familiar with the discussions said many people in Team Vance are hoping to severely pull back on the power of senior strategist Jessica De Grazia, a former Morgenthau chief assistant DA who sources said contacted sitting ADAs and asked them to work nights and weekends or to sit on a policy committee.

De Grazia, who several sources said wouldn’t have joined Team Vance months ago without Morgenthau’s tacit blessing, denied the move to The Post, although multiple sources confirmed it had taken place. Morgenthau has a long-held ban on ADAs doing political work, and some of those who got calls asked their supervisor about it, prompting an internal email reminding people about the prohibition, sources said.

“She’s a problem,” said one source close to the campaign for Vance, who has been widely described as Morgenthau’s preferred successor as he ends his nearly 35 years in office at the end of 2009. Another source said they expected she would no longer be working for the campaign soon, although Vance spokeswoman Barbara Thompson strongly denied that was the case and said her plan had always been to travel back and forth between New York and her home in London.

At the moment the race to replace Morgenthau comprises Vance, a former ADA and trial lawyer who spent a chunk of his career in Seattle before moving home in 2004; former judge Leslie Crocker Snyder – who ran against the DA four years ago, making hay of his age; and another former ADA, gun control advocate and lawyer Richard Aborn.

Crocker Snyder spokesman Michael Tobman took a swipe at Vance over the De Grazia calls, saying, “It’s sad, thought not surprising, that Vance supporters needed to behave this way since – to be plain about it – their candidate has been back in New York just five years after living sixteen in Seattle.”